Over the weekend I bought a pair of Aegirs to run as mono blocks. I ended up exchanging them for Vidars. I was using them in my home theater. They were feeding a pair of Polk LsiM 707 towers, which are not the most efficient speakers. 86db I think. I could not get enough volume out of the Aegirs and anytime a big action sequence came with a lot of noise the protection circuit would kick in and cut the amps. NOT ideal. They did sound great, but I would say they are not great with less-efficient speakers. I have not even had a chance to really stretch the legs on the Vidars yet, but so far the 400 wpc in mono is definitely pretty great for action movies!